1. Field of the Invention
The present invention generally relates to an ice discharging apparatus of an ice dispenser and more particularly to the ice discharging apparatus which is composed of a door closed under the action of a torsion coil spring and adapted to be opened by a door actuator. More specifically, the present invention concerns an improved structure of the torsion coil spring.
2. Description of the Related Art
In the hitherto known ice dispensers, a variety of doors for openably closing an ice discharging port are employed in combination with various types of door actuators. A typical structure of the prior art ice discharging apparatuses is shown in FIGS. 11, 12 and 13 of the accompanying drawings, which will be described below.
Referring to FIG. 11, there is shown a hitherto known ice dispensing apparatus, wherein reference numeral 2 denotes an ice storing chamber or box, 2a a discharge port, 3 a door actuator, 4 an openable door, 5 a solenoid, 5a a movable armature member, 6 a link, 7 a torsion coil spring, and 8 a supporting shaft on which the door 4 is rotatably or swingably mounted. In operation, assuming that the solenoid 5 is electrically energized by a control apparatus (not shown), the movable armature member 5a is magnetically attracted by the solenoid 5, as the result of which the openable door 4 which is pivotally connected to the movable armature member 5a by way of the link 6 is caused to rotate about the supporting shaft 8, whereby the ice passage or discharge port 2a leading to a dispensing port is set to the opened state. After a predetermined amount of ice has been discharged, the solenoid 5 is deenergized in an automatic manner by the control apparatus. At that time, the door 4 is rotated under the resilient restoring force of the torsion coil spring 7 to the state where the ice passage or port 2a is closed.
Referring to FIGS. 12 and 13, the torsion coil spring 7 as employed is of a substantially cylindrical form having a uniform coil diameter and coil turns wound closely to one another. Extending from the opposite ends of the torsion coil spring 7 are arm portions 7b and 7c, one of which has a hook secured to a stationary part of the ice storing box 2 with the other being fixed to the door 4.
More specifically, a main coil portion of the torsion coil spring 7 is mounted around the supporting shaft 8, while the hook of the arm portion 7b is fitted in a retaining hole 2c formed in a base plate of the door actuator 5 with the other arm portion 7c being bonded to the door 4, as is shown in FIG. 11.
When the door 4 is opened, the torsion coil spring 7 is placed under a load through the arm portions 7b and 7c, resulting in that the coil diameters (inner and outer diameters) are reduced. When the door 4 is closed, the load is substantially removed, allowing the coil portion to resume the original diameter.
As will be appreciated from the above description, in the hitherto known ice discharging apparatus of the ice dispenser including the door adapted to be opened by the door actuator equipped with the control means, the torsion coil spring serving for closing the door 4 once opened for discharging a predetermined amount of ice is constituted by a coil having a uniform diameter and is mounted around the supporting shaft (which may be a shaft secured unrotatably or mounted rotatably together with the door 4) which has a smaller diameter than the inner diameter of the coil of the torsion coil spring. Consequently, when a load is applied due to the opening operation of the door 4, the inner coil surface of the torsion coil spring 7 is not only brought into contact with the outer surface of the supporting shaft 8, but also caused to move or slide in contact with the surface of the supporting shaft (because the torsion coil spring is twisted in the rotating direction of the door 4 relative to the stationary part of the ice dispensing apparatus). In that case, both the end portions of the torsion coil spring are not only subjected to the maximum stress, but also undergo wear or abrasion because of the sliding movement mentioned above, giving rise to a problem that the torsion coil spring is likely to be broken particularly at the end coil portions which are in contact with the supporting shaft 8 as indicated at D. Moreover, another problem will concurrently arise that the end portions of the coil as broken away drop into ice being discharged, presenting a danger to an ice consumer.